The present invention relates to lightweight portable electrical apparatus, and in particular, generators.
In general, portable DC generators are known. Portable generators commonly comprise a conventional diesel or gasoline powered engine having a crankshaft coupled to a generator. The generator includes a stationary stator, and a rotor disposed for rotation with the engine shaft. The rotor generates a magnetic field. As the magnetic field intercepts windings on the stator, electrical current is induced. The induced current is typically applied to a bridge rectifier, sometimes regulated, and provided as an output. Examples of such prior art generators include the Generac G1000 (950 watts and 49 pounds), the Honda EX1000 (1000 watts and 57 pounds) and the Yamaha EF1000 (1000 watts and 55 pounds). While typically not found in portable units, an AC output can be provided by applying the DC signal to an inverter.
While referred to as portable, the prior art generator units tend to be heavy and unwieldy, or are incapable of providing sustained power sufficient for typical uses. Further, the prior art units typically provide either a relatively low amperage, high voltage (e.g., 115 volts) output, or a relatively low voltage, high amperage output (e.g., 12 or 24 volts, at from 25 to 200 amperes) and weigh from approximately 40 to 65 pounds, dry weight. In many instances, however, it is desirable to have both high voltage low current outputs, e.g., to run lights or power tools, and a low voltage high amperage output for, e.g., charging batteries or jump starting a car from a unit that is easily carried by one person using a shoulder strap.